Handhole cap



Patented Apr. 29, 1924.

ITD STATES firana PATENT OFF-ice.

FREDERICK HACHMANN, OF LOUIS, MISSOUBI, ASSIGNOR TQ VTILLIAM H. GREGG,

OF ST. LOUIS, MISSOURI. i

;ranni-zona can:

Application filed January 17, 1921. Serial No. 437,755.

To all 107mm it may 0001002171:

Be it known that I, FREDERICK HACH- MANN, a citizen of the United States, and

resident of the city of St. Louis, State of Missouri, have invented certain new and useful Improvements in Handhole Caps, o-f which the following is a specification containing a full, clear, and eXact description, reference being had to the accompanying drawings, forming a part hereof.

My invention relates to improvements in hand hole caps, and has for its primary' object a hand hole cap for use in boilers, oi] still, and the like, and one in which the use f of a gasket is entirely eliminated.

A further object is to construct a hand hole cap which does not require the use of a rolling in tool to seat it.

In the drawings:

Fig. l is a sectional view of my iinproved cover, showing the same seated in a boiler sheet;

Fig. 2 is a side elevation of the same;

Fig. 3 is a face view;

Fig. 4 is a vertical cross section of a modifled form of hand hole cover, showing the same seated in a boiler sheet;

Fig. 5 is a cross sectional view of the same before being seated;

Fig. 6 is a Vertical cross sectional view of a. modified form of a hand hole cap, showing the same seated in the boiler Sheet;

Fig. 7 is a similar view before being seated; and

Fig. 8 is an elevation of the wrench made use of for seating the cap.

In the construction of my device I employ a cup-shaped member having a cylindrical wall 9. This wall is provided on its edge with the inwardly inclined portion 10. Formed integral with the wall-9 is a dishshaped port-ion 11, which is provided in its center with a rectangular depressio-n 12. That portion of the wall 9 adj acent the cover 11 is provided with an outwardly extending bead or flange 13. This much of my device made by staniping and drawing the same out of a sheet of metal.

After the cover has been formed, it is next given a coating 14. This co-ating is p-referably of zinc because the zinc has the peculiar characteristic of forining a binder between the cap and the edge of the hand hole. Before inserting the cap in the hand hole, the hole is first prepared by means of a suitablev tool'so thata po-rtion of the periphery willbe cylindrical, as indicated by the numeral 15, and a portion tapering, as indicated by the numeral 16, this corresponding to the portions9 and 10 of the wall of the cap. AfterV the holehas been thus prepared, the cap is seated therein from the inside of the boiler shell` and given a slight tap' with a. liammer. The rectangular portion 17 of the wrench 18 is then inserted in the rectangular depression 12 and the capy given a partial turn. This partial turning will upset the grain of the zinc and this upsetting of grain will have a tendency to prevent the cap from being pushed out of the hole when accidentally bumped against, although it does not interfere with the removal of the cap when it is necessary to open the hand hole.

The cap is also further firmly seated by -t-he pressure inside the boiler acting against the dish-shaped portion 11, while the bead or flange 13 will prevent the cap being forced entirely through the hole.

^ In Figs. 1 and 5 I have shown a modified form in which the dish-shaped portion 11 is provided With a. bead or flange 13, and formed integral' with this fiange 13 is a cylindrical wall 19, its front end being tapered, as indicated by the numeral 20. rl`his tapering is done by imparting additional Vpressure to the wall 19, so that the metal beco'ines thinner. In the use of this cap a rolling in tool is necessary, since the hole in the boilersheet is provided with the cylindrical portion 21 in which a groove 22 is formed, while preparing the hole for the reception of the cap. This groove 22 is, however, very slight, being in actual practice only about two-thousandths of an inch deep, a-lthough this depth may be varied as found desirable.

This cap is also provided with the rectangular recess 12 and the zinc coating 14. This coating holds the cap after the cap has been removed from the hole and replaced, since the groove 22 is so slight as to allow the material to be sprung out of it and back again, by the use of a little force.

In Figs. 6 and 7 I have shown another inodification. This form is also provided with the dish-shaped cover 11, the central recess 12 and the head or fiange 13, and formed integral with the fiange is the cylindrical wall 23, which has its outer edge b-eveled, as at 24:. This cap, after being formed,

llU

is given the coating llvof zinc. The hole in the boiler sheet is provided With the cylindrical portion 25, which is adjacent the outer face of the boiler sheet; Adjacent this' cylindrical po-rtion is fo'rined a depression 26,

which corresponds to the taper or bevel 24;, and adj acent the depression 26 the hole fiai'es inwardly, as indiceted by the nun1eral27. In seatng this cap, it is also necessary to use a, tool for the first seatingr; the subsequent seatings are per-foi'ined merely by' a haniiner and the wi'ench 18. The inclina-tion of the tapered poi'tion is VeryV slight, approximately the saine as the depth of the groove 22, so

= that the cap canbe. forced out of place and gather in these Virregularities and prevent lea-kage around the edge of the hole.

Having fully described iny inVentio-n, What I ela-im is:

A hand hole cap formed from a single sheet of relatively thick material, and provided With a dish-shaped closed end, a. cylin-V drical Wall foi'nied integral With said dishshaped end, an outwardly extending fia-nge circulai' in cross section foi'ined integral With the Wall and end, the materia-l in which the wall is formed 'being drawn down thinnei' at its free open end than at the end adjacent the flange, coating of soft material of uniforin thickness incasing said cover, Wherehy a leal: proof joint is obtained, the dishshaped cover being ;provided With a means for' receiving a wi'ench Whereby the cap Ina-y be tightly seated in a. crown Sheet Without the use of e rollingt-in too-l or expander.

In testiinpny Whereof,V I haveV signed iny name to this specification;

FREDERICK HACHMANN. 

